Shredder-compactor

ABSTRACT

Apparatus for reducing in volume by compaction organic and inorganic waste material or garbage. An auger-compacter effects shredding or shearing of the waste material into shreds or particles compacted and reduced in volume and delivered as the output. Shearing or shredding is accomplished by coaction of the auger and slots in a compaction tube within which the auger is rotatably disposed. The slots are disposed extending axially of the compaction tube on the upper part thereof and are circumferentially spaced. A breaker or shredder-bar in a hopper receiving the waste material may be provided upstream of the slots to coact with the auger in shredding or shearing the waste material or garbage before introduction into the compaction tube.

I United States Patent 11 1 1111 3, DeMilt et a]. Sept. 25, 1973 SHREDDER-COMPACTOR 3,044,391 7/1962 Pellett l0O/l48 1751 Kenneth E. new, Scotch Plains: i239"??? 1311333 flfiifitaziiiji 131133333: #88135? Stephen Amboy; 1,007,622 10/1911 Wurl l()0/DIG.- 3 Henry Gardner Scholer, Carteret, all of Primary ExaminerBilly J. Wilhite [73] Assignee: Mil-Pac Systems, Inc., Mountainside, Bums and Emmanuel Lobaw NJ. 22 Filed: Aug. 18, 1970 [57] ABSTRACT Apparatus for reducing 1n volume by compact1on or- PP 64,698 ganic and inorganic waste material or garbage. An auger-compacter effects shredding or shearing of the waste [52] s Cl "loo/98 R, loo/147, loo/DIG 3 material into shreds or particles compacted and re- 0 /DIG. 8 duced in ,volume and dehvered as the output. Shearmg 51 1111.01 B30b 15/08 Shredding is acwmplished by coactio" of the auger [58] Field of swat... IOO/DIG. 3, DIG. s, F tube which loo/39 41, 94, 95, 96, 98, 147 148 1s rotatably d1sposed. The slots are d1sposed extendmg axially of the compaction tube on the upper part 56] References Cited tillereitf argd are cirltlzumferentially spzttkcied. Atbreakter s re erar 1n a opper rece1v1ng e was e ma er1a UNITED STATES PATENTS may be provided upstream of the slots to coact with the s auger in shredding or shearing the waste material or c 1c eysen... 1,506,036 8/1924 wmmanh l I I I I loo/97 X garbage before mtroductlon into the compaction tube. 1,722,882 7/1929 Anderson 100/98 6 Claims, 13 Drawing Figures L :1 I F 1 iunve lll lell' llll 3 till!" 11111 'HHH" 1- Z .59 I :T 1 3 1 1 1 3 111 1g 11111, 7 3. 111111 /2 11 11 IHHI' 6 1 SHREDDER-COMPACTO This invention relates generally to processing of organic and inorganic waste materials and more particularly to a new improved apparatus for processing waste material or garbage.

Apparatus and methods of processing garbage and trash are known in which the waste material is comminuted and is then compacted to reduce the volume thereof. The apparatus of this type have heretofore used a reduction'mill or pulverizer for comminuting the waste material and then feeding it through a feed chute to a compacter. These known apparatus are relatively complex and expensive to make.

The known hammer mills or pulverizers receive the waste material to be comminuted and may have a first stage in which the material is broken up before it passes downwardly to a second stage where cutting hammers or flails reduce the waste material to smaller particles. The size of the particles may be substantially controlled by breaker plates which are adjustable inwardly and outwardly relative to the interior of the hammer mill or pulverizer to controllably set the clearance between these plates and the cutting hammers in the second stage of the mill. The comminuted material is discharged centrifugally by positive air flow developed by the mill and sweep hammers positioned below the cutting hammers.

The comminuted material is received in a feed chute from which it is delivered to a compacter which may be made as a compacter-extruder. The feed chute has presented a problem in this type of apparatus in that its interior is generally covered by adhering comminuted material which adheres to the interior of the chute because of charges carried by the particles and provision must be made for delivering the adhered material to the compacter. This has resulted in the construction of tamper devices within the feed chute to assure positive delivery to the compacter. I

The compacters themselves may be made as a combination compacter-extruder. Such compacter-extruders have been constructed as auger-compacters-that comprise a helical screw mounted rotationally within a tube. The helical screw is constructed so that the angular friction is such that the screw effects compaction and reduction of volume of the comminuted garbage and discharges the compacted garbage greatly reduced in volume.

It is a principal object of the present invention to provide an apparatus for processing garbage to reduce its volume by a simple, substantially maintenance-free mechanical system free of the need of a hammer mill or pulverizer.

According to the invention a shredder-compacter receives waste material to be compacted. The waste material is delivered to the apparatus as a mixture of organic and inorganic materials randomly mixed and may be wet or dry. The materials are shredded as necessary by the auger-compacter in cooperation with a shredding device and is transported axially through the apparatus by a helical screw of the auger-compacter which further reduces the material to particles which may be compacted. The shredded material is received within a compaction tube and compacted therein. The helical screw or auger is constructed so that the angle of friction is such that the screw effects compaction and reduction of volume of the garbage particles and discharges the compacted garbage greatly reduced in volume.

Other features and advantages of the apparatus in accordance with the present invention will be better understood as described in the following specification and appended claims, in conjunction with the following drawings in which:

FIG. 1 is a perspective and elevation view of apparatus according to the invention;

FIG. 2 is a section view taken along section line 2-2 of FIG. 1;

FIG. 3 is a section view taken along section line 3-3 of FIG. 2;

FIG. 4 is a fragmentary plan view of the apparatus illustrated in FIG. 1;

FIG. 5 is a sectionview taken along section line 5-5 of FIG. 4;

FIGS. 6-8 inclusive are section views of different embodiments and modifications of part of a compaction tube of the apparatus and are views taken along modified apparatus at points comparable to that of FIG. 5.

FIG. 9 is'a fragmentary enlarged view of a part of the apparatus in FIG. 2;

FIG. 10 is a section view taken along section line 10-10 of FIG. 1 and FIGS. 11-13 inclusive are section views of modifications of the portion of the apparatus shown in FIG. 3.

The apparatus hereinafter described reduces solid waste material or garbage by greatly reducing its volume and may be used to process, by shredding, shearing and reduction in volume, paper, glass, plastic, metal cans and other wet and dry solid organic and inorganic materials and waste. The apparatus compresses the shredded product to as little as a very small fraction of its original volume, extracting excess moisture as hereinafter described and the end product or output is a compressed, relatively dry waste. While the apparatus will be described for processing garbage and waste of the above-described type, it will be understood by those skilled in the art that other materials of a similar nature may be similarly processed by the apparatus of the invention.

The apparatus according to the invention comprises -a shredder-hopper 10, mounted on a base or skids 11,

for receiving garbage or waste material constituting organic and inorganic wet or dry materials randomly mixed. Within the lower end of the shredder-hopper 10 is provided a shredder or breaker bar 12 whose operation is hereinafter described. The shredder-hopper is in communication with an auger-transport constituting a leading portion of a stepped pitch helical screw 13 extending axially through a compaction tube 14 which is in communication with the hopper 10, to which shredded particles are delivered for compaction as later described herein.

The helical screw 13 is driven from an electric drive 15 having a reversible electric motor 16. The drive is provided with a thrust bearing, not shown, receiving the axial thrust of the helical screw. The entire assembly, other than the controls, is mounted on the skid or base 11.

The waste materials received in the shredder-hopper 10 are torn, sheared or shredded by the breaker or shredder-bar 12 extending axially the length of the shredder-hopper 10 in the lower part thereof in position parallel to the helical screw to coact with the flights of the helical screw 13. As the helical screw is rotationally driven, in the direction shown by an arrow, it feeds the larger waste material into the shredder bar and as it rotates its flights jointly with the shredder-bar will shred, shear and tear the materials such as wood, cans, plastic etc. and reduce the size thereof. The helical screw is provided with a leading auger-transport section, as illustrated in FIG. 2, within the shredderhopper l and has its larger pitch in this portion for transporting larger materials and in order to have a large span of the flights coacting jointly with the edge surfaces of the shredder-bar to effect the shredding and tearing action along the full axial length of the shredder-hopper 10. Moreover, the long pitches section of the screw is assisted in transporting the waste material. The shredder bar resists rotation of the waste material by the screw and thus constrains the material in the hopper to axial travel.

The shredder or torn waste material is transported from the shredder-hopper into the compaction tube or auger-compacter 14. The shredded particles of garbage are advanced axially through the tube. The particles pass through two transition zones in the tube in which larger particles are shredded and in a second and downstream transition zone the reduced particles are pushed at an effective angle of friction, as later described, for compacting them and reducing the volume thereof.

In the first zone smaller particles and shreds of shredded garbage being transported by the helical screw are disposed in the flow of material substantially in the lower half of the compaction tube. The larger particles are moved axially through the tube within the upper part of the tube and are subjected to shredding and reduction in size by axially extending slots 18, 20 disposed circumferentially spaced from each other as illustrated in FIGS. 4 and 5. The slots extend through the tube and axially thereof and are sealed-off with cover plates 21, 22. As the larger waste material is advanced rotationally and axially through the tube the flights of the helical screw, which in this section of the screw have a smaller pitch, will coact with the edges and sides of the tube slots, defining the slots, to effect tearing, shearing and shredding action so that the larger particles are further reduced in size and will be moved downwardly to the lower part of the tube to make room for further treatment of the larger particles. The slots extend axially at least the axial length of the pitch of the helical screw in this zone of the compaction tube. It has been found that apparatus according to the invention will function to reduce the size of the waste material received in the hopper without the use of a shredder-bar 12 so that the auger-compacter 12, 14 functions as a shredder-compacter. However, the action of the apparatus is improved by the use of such a shredder-bar.

As particles of garbage are advanced axially through the compaction tube the particles pass through the second transition zone in the tube, which is downstream of the first zone or shredding zone, in which each particle is pushed at an effective angle of friction, for example 55.3, because of the angle of the helical screw 12 and the friction. It is necessary for the particles to slide against this screw in order to be compacted. It has been found that a coeffecient of friction of the particles of at least 1.73 and/or angular friction of 55.3 is required to compact the matter in a garbage mixture which is composed both of organic and inorganic material which may be wet or dry. If the angle is less, as it is for example in the center of the screw, and perhaps be cause various materials are involved slippage occurs and as soon as there is slippage within the compaction zone the plug of compacted material will over-heat rapidly, which may cause jamming. This is avoided and relieved as later described. However, the principal compaction takes place at the downstream end portion of the helical screw closest to the outlet of the compaction tube or shredder-compacter. In order to improve the compaction it has been found that if the flight of the screw nearest the output end of the tube is constructed as illustrated in FIGS. 9-10 as a cut flight the apparatus will operate better as later described.

The compacter screw 13 has an end flight 30 cut" or terminating as illustrated in FIGS. 9-10 and has a radial plate or compacting blade 32 and its reinforcement 33. The blade has a width determined as later explained. The blade 32 is disposed in a plane substantially transverse to the longitudinal axis of the shaft of the compacter helical screw 13 and has a radial extent or height corresponding substantially to the height of the individual flights of the compacter screw. The radial blade is disposed in a plane substantially constituting an extension of the cut flight" 30.

The plate or blade 32 is fixed on a shaft 13a of the screw 13. Since the plate has a radial dimension such that its radial extent is equal to that of the flights it cooperates with the cut flight in compacting the material as later described. The blade is disposed in a plane transversely of the longitudinal axis and this plane is offset about l6 to a plane transverse and normal to the longitudinal axis of the helical screw so that it is disposed offset to the longitudinal axis of the screw as shown in FIG. 1. The plate is disposed next to the downstream end of the helical screw. This transverse blade or plate 32 is of a width of about one half the difference dimension between the dimension of the outside diameter of the screw shaft and the overall diameter of the screw flights. The transverse end blade is thus offset relative to a plane normal to the shaft axis and is dimensioned in width so that the tube is not closed off, as can be seen in FIG. 10.

In order to effect compaction, the length of the tube downstream of the compacting screw must be sufficiently long to provide enough of a restriction to the plug of material developed downstream of the helical screw in order to obtain good compaction ratios. If it is desired to obtain the same compaction with a shorter tube, it has been found that the screw must either be constructed of hardened steel so that it does not wear excessively or a restriction may be provided, not shown, in known manner. Moreover, if the tube is constructed as a solid tube, the length of the compacter tube, if too great, will cause jamming downstream of the screw because of excessive swelling of the plug of material developed downstream of the screw.

The principle of compaction relied on in the invention is that compressibility and the coefficient of friction of the materials involved, as well as the angular friction, permit the compaction required. However, the compressibility and coefficient of friction of these materials can vary considerably, for example moisture can influence the friction factor greatly, and in order to compensate for these variables, a nozzle of variable cross-section area is provided in the invention. This nozzle automatically changes its area of cross-section to compensate for changes in physical properties of the plug" and avoids jamming of the tube in the event that the compacted material swells.

The variable cross-section change possible and construction of the nozzle is illustrated in FIG. 1 in which the nozzle is constructed as a latch made as a pivoted lid or section 50 movable radially outwardly relative to the longitudinal .axis of the tube. This lid section of the tube is provided with outwardly extending flanges 55, 56 on opposite sides thereof. The lower part of the tube is provided with outwardly extending lugs 58, 59 spaced circumferentially from and aligned with respective flanges of the lid for mounting variable adjustable means, for example spring-loaded bolt assemblies 61, 62, 63, 64. The spring-loaded assembly 61 is provided with a manual-adjust knob 61a. The assemblies may be mounted so that they can be swung into position through slots, not shown, provided in the corresponding flange or lug 55. Those skilled in the art will understand that pneumatic-hydraulic devices with variable orifices, not shown, could be used instead of the spring-loaded bolt assemblies. Each of the springloaded bolt assemblies will allow the lid or sections to move upwardly and substantially radially of the corresponding lower section of the tube. It can thus be seen that the lid can be variably adjusted to in effect provide a device for precluding jamming of the compacted material downstream of the screw and in effect provide a variable packer lid arrangementor automatically variable nozzle or latch having a minimum cross-section area changing in an increasing direction depending upon the adjustments set on the spring-loaded assemblies of the individual lids. This device will relieve the tensions in the compacted material.

The packer lid is an upper hemispherical part of the tube 14, as illustrated, and is secured to the lower hemispherical section of the tube and pivotally mounted thereto by a hinge 67. The four variably adjustahle spring-loaded bolt assemblies will allow the lid to swing so that in the event of excessive internal pressure on the lid 55 it will move outwardly sufficiently to preclude jamming of the screw and-tube due to the plug of compacted material being frozen in the tube 14. The increase in cross-section of the tube allowed by the pivotally mounted lid or section is sufficient to compensate for swelling that may take place in the plug" of compacted material without any compacted material being allowed to escape between the lid and tube. The tube and lid section are constructed as shown in FIG. 10 along the length of their cooperating surfaces so that longitudinal seams 14a, 14b are formed and compacted material cannot escape as the lid 5d moves pivotally relative to the tube.

The variable nozzle or latch described above relieves the internal tension of the compacted material and still maintains a good compaction ratio. This provision avoids jamming; however, provision may be made for electrically protecting the apparatus in the event the compacter screw freezes or becomes jammed because of its inability to advance the plug of compacted material.

The apparatus above described requires resistance to the particles of material for compacting. Compaction takes place in the tube and the desired compaction can be accomplished solely by thescrew without the compacting blade 32 described above. In order to provide resistance to the material, a nine inch diameter compaction tube should extend at least about four inches downstream of the compacter screw blade. The portion of compacter tube between the downstream end of the compacter screw and upstream of the automatically variable nozzle is about four inches. However, the use of the compacting blade improves the compaction ratio. The transverse compacting blade 32 developes only axial forces that greatly compact the material in the 4 inch length of tube downstream of the compacter screw and upstream of the nozzle or latch arrangement. This is in contrast to compacting solely with the screw where radial forces are developed that are lost energy to the principal compaction function.

While same known compacters using an auger in combination with a reduction mill require closing off the outlet or discharge end of the auger to start the compaction by the apparatus and to keep material from being blown out the present apparatus avoids this need since there is an absence of a reduction mill. The apparatus according to the invention starts its compacting without a temporary resistance being built up to the discharge by temporary blocking off of the discharge end.

The construction described above provides an apparatus free of hydraulic systems and their attendant problems. This construction requires considerably less power in effecting compaction than the known systems. For example, a 7.5 HP. electric motor rotating at 51 R.P.M. geared down in a 17.9 1 reduction double helical reduction gear drives a 1.81:1 reduction pulley and belt so that a compacter screw having 9 inch diameter flights develops 1,820 lbs. of thrust and will have a cubic foot displacement of 14.02 cfm with a desirable compaction ratio.

It can be seen that the elimination of the reduction mill will reduce power requirements and maintenance. Moreover, the present apparatus operates much more quietly than known apparatus and is constructed compactly so that it may be installed in less spacethan known apparatus and without need to consider noise abatement.

' The slots and cover plates therefore can be com structed differently than before described. Thus, as illustrated in FIG. 6 a compaction tube 64 has slots 65, 66 covered with axially extending raised covers 68, 69 which are rectangular in cross section. The slots extend inwardly of the cover to allow for wear of the sides of the slots. The same provision is made in the embodiment illustrated in FIGS. 1-5 and FIGS. 7-8. In FIG. 7 a compacted tube 74 has slots 75, 76 having covers 78, 79 which are triangular in cross section. The covers illustrated in FIGS. 6 and 7 are raised and define a space 68a, 78a, 79a outwardly of the respective compaction screw in communication with the interior of the respective screw tube. This space allows the material to extend into this working space and thus the full sides of the slots can effect shredding in conjunction with a respective helical screw 62, 72.

The embodiment in FIG. 8 illustrates a compaction tube 84 having axial slots covered with plates 88, 89 bolted down instead of welded as illustrated in FIG. 5'. In these two embodiments, FIGS. 5 and 8, the plates are flush with the exterior of the respective compaction tubes 14, 84 and the slots cooperate with the screws 13, 82 as before described.

The breaker bar 12 may be constructed with a different cross section than that illustrated in FIG. 3. Thus, in FIGS. 11-13 inclusive modified shredder-hoppers 111, 112, 113 are shown in cross section in which respective breaker bars 114, 116, 118 are bolted on the side of the hopper in position to provide a longitudinal edge coating with the flights of the respective helical screws 120, 121, 122. The breaker bars or shredderbars disclosed in these latter FIGS. effectively carry out shredding of the waste material in a manner before described with respect to the first embodiment described and shown in FIG. 3. Moreover, these shredder-bars or breaker bars each cooperate with the individual helical screws to deliver the waste material axially of the individual helical screws and into respective augercompacter tube, not shown, connected to each respective shredder-hopper l1 1, 112, 113 as before described.

While the invention is described as breaking, shearing and shredding the material it will be understood that the term shredding as used herein also includes the actions of breaking, tearing and shearing the material and the term is used generically to all of these actions.

What we claim and desire to secure by Letters Patent 1. An auger-compacter for compacting organic and inorganic waste materials randomly mixed comprising, a tubular member, means comprising said tubular member for receiving the waste material, shredding and compacting said waste material comprising a driven auger-compacter screw disposed axially in said tubular member, having helices and a downstream end flight having a sector removed therefrom for compacting said waste particles in said tubular member, a pair of slots disposed diametrically of said screw and disposed parallel to the longitudinal axis of said compacter screw extending axially of said compacter screw axis and upstream axially of said downstream end flight, and a transverse blade disposed in a plane transverse to the longitudinal axis of said compacter screw adjacent said end flight and disposed offset relative to a plane transverse and normal to said axis.

2. Apparatus for reducing the volume of wet and dry solid organic and inorganic waste material of different densities randomly mixed comprising, an augercompactor having shredding means to shred the waste material, compaction tube, a rotationally driven helical screw disposed extending axially, in said compaction tube, means on said helical screw cooperating solely with said tube for compacting the shredded waste material comprising helices on said helical screw and a cut flight at a downstream end of said helical screw, said means on said helical screw for compacting the shredded waste material including blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said out flight.

3. Apparatus for reducing the volume of waste material such as garbage and the like comprising, shredding means having means to shred waste material such as garbage and the like, means in communication with said shredding means to receive the shredded waste material from said shredding means comprising an auger-compacter having means receiving the waste material and including means to compact the shredded waste material to reduce it in volume and deliver it as an output of said apparatus, said means to compact the shredded waste material comprising a compaction tube, a helical screw disposed extending axially in said compaction tube, means on said helical screw cooperating with said tube for compacting said shredded waste material comprising helices on said helical screw and a cut flight disposed downstream of said helices, a blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said cut flight.

4. Apparatus for reducing the volume of waste material comprising, a shredder to shred organic and inorganic waste material received therein in a random mixture, an auger-compacter in communication with said shredder to compact and reduce the volume of shredded waste material having means comprising a driven helical screw to compact waste material and deliver it as an output of said apparatus, said auger-compacter comprising a compaction tube within which said helical screw is disposed extending axially therein, means on said helical screw cooperating with said tube for compacting said shredded waste material, said means on said helical screw for compacting comprising helices thereon and a cut flight disposed at a downstream end of the helices on said helical screw and including a blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said cut flight.

5. Apparatus for reducing the volume of waste maerial such as garbage and the like comprising, shredding means for shredding solid waste material and an auger-compactor receiving the shredded waste material to compact it and reduce it in volume for delivery as an output, said shredding means and said augercompactor comprising a driven, common, single helical screw, said shredding means comprising helices on said helical screw upstream of said auger-Compactor and elongated means defining an elongated edge along the axial extent of said helices for shredding waste material driven by said helices, said auger-compacter comprising a tube within which other helices downstream of the first-mentioned helices are rotatably driven, said shredding means comprising means for receiving and containing said waste material and within which the first-mentioned helices and said elongated edge are disposed, said tube having an inlet end disposed communicating with said means for containing the waste material.

6. Apparatus for reducing the volume of waste material according to claim 5, in which said tube comprises at least one axial slot having axial edges bounding the slot cooperative with helices within said tube for shredding waste material within said tube. 

1. An auger-compacter for compacting organic and inorganic waste materials randomly mixed comprising, a tubular member, means comprising said tubular member for receiving the waste material, shredding and compacting said waste material comprising a driven auger-compacter screw disposed axially in said tubular member, having helices and a downstream end flight having a sector removed theRefrom for compacting said waste particles in said tubular member, a pair of slots disposed diametrically of said screw and disposed parallel to the longitudinal axis of said compacter screw extending axially of said compacter screw axis and upstream axially of said downstream end flight, and a transverse blade disposed in a plane transverse to the longitudinal axis of said compacter screw adjacent said end flight and disposed offset relative to a plane transverse and normal to said axis.
 2. Apparatus for reducing the volume of wet and dry solid organic and inorganic waste material of different densities randomly mixed comprising, an auger-compactor having shredding means to shred the waste material, compaction tube, a rotationally driven helical screw disposed extending axially, in said compaction tube, means on said helical screw cooperating solely with said tube for compacting the shredded waste material comprising helices on said helical screw and a cut flight at a downstream end of said helical screw, said means on said helical screw for compacting the shredded waste material including blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said cut flight.
 3. Apparatus for reducing the volume of waste material such as garbage and the like comprising, shredding means having means to shred waste material such as garbage and the like, means in communication with said shredding means to receive the shredded waste material from said shredding means comprising an auger-compacter having means receiving the waste material and including means to compact the shredded waste material to reduce it in volume and deliver it as an output of said apparatus, said means to compact the shredded waste material comprising a compaction tube, a helical screw disposed extending axially in said compaction tube, means on said helical screw cooperating with said tube for compacting said shredded waste material comprising helices on said helical screw and a cut flight disposed downstream of said helices, a blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said cut flight.
 4. Apparatus for reducing the volume of waste material comprising, a shredder to shred organic and inorganic waste material received therein in a random mixture, an auger-compacter in communication with said shredder to compact and reduce the volume of shredded waste material having means comprising a driven helical screw to compact waste material and deliver it as an output of said apparatus, said auger-compacter comprising a compaction tube within which said helical screw is disposed extending axially therein, means on said helical screw cooperating with said tube for compacting said shredded waste material, said means on said helical screw for compacting comprising helices thereon and a cut flight disposed at a downstream end of the helices on said helical screw and including a blade coaxial with said screw and in a plane transverse to the longitudinal axis of said screw and extending outwardly on said screw, and said blade being disposed adjacent said cut flight.
 5. Apparatus for reducing the volume of waste maerial such as garbage and the like comprising, shredding means for shredding solid waste material and an auger-compactor receiving the shredded waste material to compact it and reduce it in volume for delivery as an output, said shredding means and said auger-compactor comprising a driven, common, single helical screw, said shredding means comprising helices on said helical screw upstream of said auger-compactor and elongated means defining an elongated edge along the axial extent of said helices for shredding waste material driven by said helices, said auger-compactor comprising a tube within which other helices downstream of the first-mentioned helices are rotatably drivEn, said shredding means comprising means for receiving and containing said waste material and within which the first-mentioned helices and said elongated edge are disposed, said tube having an inlet end disposed communicating with said means for containing the waste material.
 6. Apparatus for reducing the volume of waste material according to claim 5, in which said tube comprises at least one axial slot having axial edges bounding the slot cooperative with helices within said tube for shredding waste material within said tube. 